So it just never seizes to amaze me all the beautiful craftmanship that some members of the forum goes through, to make sure the parts of R2D2 is up to par! So even an R2 detail which mostly is visible in only one of the movies, can be reproduced to such a detail! This is the life-form scanner, from The Empire Strikes Back.
Wow, its just stunning!
Each part manufactured may only be available in small quantities and for a short amount of time. Since these are not produced for any commercial use, only in limited numbers for re-sale to members of the forum. So mostly you could scout the forum for the next part-run or start building your own and try to follow the screen accuracy.
R2D2 really is a swiss-army-robot when you look at all his devices!
...I guess collecting piece by piece when available, and see which parts you can make for yourself is one way to go at it...